The Presbyterian Church in the U.S. (PCUS) formed as a result of southern Presbyterians withdrawing from the main national body of Presbyterianism during the Civil War. After Confederates fired on Fort Sumter (April 12-14, 1861), the General Assembly of the northern Presbyterian Church met in Philadelphia and declared its loyalty to the United States. However, most of the southern delegates were not present. The decision to make such an important political decision without them was a proverbial "slap in the face." Southern presbyteries began to withdraw from the main national body and formed the Presbyterian Church in the Confederate States (later named the Presbyterian Church in the United States) in December of 1861. It would take more than a century (1983) for the denomination to finally reunite with the main national Presbyterian body.